Tuna

Tuna are large saltwater fish that belong to the Scombridae family, along with Mackerel.

While tuna contains an abundance of protein, potassium, magnesium, omega-3 fatty acids, and a mini alphabet of vitamins, it also contains mercury which can be harmful to both people and pups if too much in ingested. You may see tuna listed as freshly prepared, deboned, dehydrated, fish stock, fish meal, or as fish derivatives in your dog's food or treats.